This invention relates to the conversion of chemical energy to electrical energy, and more particularly to a new and improved anode construction for lithium-halogen cells and method of making the same.
One area of use of the present invention is in providing electrical power to inaccessible devices in the human environment, for example to an implanted cardiac pacemaker, although the principles of the present invention can be variously applied. Lithium-iodine batteries are available for such use and advantageously have an open circuit voltage of about twice that of the mercury cell, do not generate gas during operation, and have a non-corrosive electrolyte.
It is desirable to maximize that portion of the internal cell volume for containing cathode material which in turn increases the theoretical ampere-hour rating of the cell. It is also desirable to maximize the lithium anode surface area in direct operative contact with the cathode material. In addition, the nature of the iodine-containing cathode material such as an iodine complex is that it can tend to flow within the cell and possibly form a short circuit path between the anode collector lead and the cathode. Therefore it is important to prevent such leakage.